Recent advances in the HL-2A tokamak experiments

Two experiment campaigns were conducted on HL-2A tokamak in 2003 and in 2004 after the first plasma was obtained at the end of 2002. Progresses in many aspects have been made, especially in the divertor discharge and feedback control of plasma configuration. Up to now, the following operation parameters have been achieved: Ip = 320 kA, Bt = 2.2 T and discharge duration Td = 1580 ms. With the feedback control of plasma current and horizontal position, an excellent repeatability of discharge has been achieved. The tokamak has been operated at both limitor configuration and single null (SN) divertor configuration. The HL-2A SN divertor configuration is simulated with the MHD equilibrium code SWEQU. The divertor experiment results were compared with the simulation results obtained with B2. When the divertor configuration is formed, the impurity radiation in main plasma decreases remarkably. The plasma performances are improved significantly after siliconization. (author)